This invention relates to the art of silo unloaders, particularly bottom unloaders. In the art of silo bottom unloaders, augers are utilized, in rotation about their own axis, and also in sweeping motion across the floor of a silo, to deliver silage toward a generally central opening, discharge chute, or passageway member at about the center thereof. An example of such an auger having central discharge for discharging silage from the bottom central portion of a silo is disclosed in my earlier U.S. Pat. No. 4,095,703. Another example of a bottom silo unloader of this type is set forth in my U.S. Pat. No. 4,057,151, wherein the radial inner end of the auger is carried by a radially moveable central support plate that is separated from the silo floor by silage discharge openings. Often, such silos employ an additional discharge auger or other lower conveyor, for conveying silage that has been discharged through the central passageway, upwardly and outwardly to the exterior of the silo, and is disclosed in my U.S. Pat. No. 4,057,152. Other types of conveyors are as disclosed in my U.S. Pat. No. 4,057,153, and these convey the silage that has been discharged through the bottom central opening in the silo floor, upwardly and out to the exterior of the silo.
Such devices as have been disclosed in my prior inventions, function very well, and particularly well, when the silage is damp and not readily flowable.
However, when silage is of a readily flowable type, such as dried corn kernels, it is possible that jamming of the passageway beneath the silo floor may occur during an overnight condition of non-use. That is, when the unloader is not being used, as during overnight, the dry, readily flowable silage may drop down through the passageway between the radial inward support for the auger and the silo floor, become packed around the drive train for the auger rotation, and become compacted around the conveyor that is disposed beneath the silo floor for the purposes of conveying discharged silage upwardly out of the silo. Such compaction can occur, whether the lower conveyor is of the belt, or auger types.
It is this problem to which the present invention is addressed.